Area codes 705, 249, and 683 are telephone area codes in the North American Numbering Plan (NANP) for most of northeastern and central OntarioinCanada. Area code 705 was created in a 1956 area code split from portions of the 613 and 519 numbering plan areas. After a reduction in geographic coverage in 1962, the numbering plan area was assigned a second area code, 249, in 2011 to form an overlay numbering plan. A third area code, 683, was added in June 2022.
Ontario received two area codes, 416 and 613, in the initial configuration of the first continental telephone numbering plan in 1947. Area code 416, in the southern part of the province, was split in 1953 to form area code 519 in the western part of the province. In 1956, area code 705 was created from portions of the 613 and 519 numbering plan areas and served nearly all of Ontario north and west of the Golden Horseshoe.[1] In 1962, the resulting numbering plan area was reduced in geographic extent by splitting off a portion with area code 807 for northwestern Ontario. Area code 705 was in danger of exhaustion, but creating a new area code was need to improve call routing from Manitoba and the rest of Western Canada to northwestern Ontario.
On March 19, 2011, the remaining 705 numbering plan area area was assigned a second area code, 249, with the configuration of an overlay plan. Since then, all calls have required ten-digit dialling.[2]
The Canadian Numbering Administration Consortium had considered "erasing" the 807-705 boundary and turning 807 into an overlay for all of northern Ontario, which would have effectively reversed the 1962 split, but did not recommend the idea for fear of potential confusion.[3]
The incumbent local exchange carriers in 705/249 are Bell Canada, Northern Telephone, Bell Aliant (Ontera), Eastlink, Nexicom, and some municipally-owned carriers.
In February 2017, area code 683 was reserved as a third area code for the numbering plan area,[4] After further debate, it was decided to activate 683 as a third overlaid area code for this region, effective June 18, 2022.[5] with an in-service activation date of June 18, 2022.
Area code 460 was reserved as a fourth area code for the region in November 2022.[6]
As of 2016, the numbering plan area has the following exchanges:
| North: 867 | ||
| West: 807, 906 | Area codes 705/249 | East: 613/343, 819/873 |
| South: 905/289/365, 519/226/548, 906, 989 | ||
| Yukon, Northwest Territories and Nunavut area codes: 867 | ||
| Quebec area codes: 367/418/581, 263/438/514, 354/450/579, 468/819/873 | ||
| Michigan area codes: 231, 248/947, 269, 313, 517, 586, 616, 734, 810, 906, 989 | ||